I have been shooting 4x5 for a few months and getting some good negatives recently. I have started trying to make some good enlargements and failing miserably. Can someone explain why a negative I scan into the computer looks good on the screen, but when I use the enlarger to make a print the colors are all crazy (the blacks are much more brown)? I shot a test strip before making the print and found the proper aperture and exposure. Do I need to use the filters (cyan, magenta, and yellow) on the enlarger? If so, how will they effect the final print?
Thanks in advance for your help. I couldn't figure all this out on my own.

If you are trying to print a color negative onto color paper then you will have to dial in the proper filtration on the enlarger to get the correct colors in the final print. You will have to use trial and error or a color analyzer to determine what filtration is needed.
Color paper is not a direct inverse of the negative.
If you are printing B&W on color paper you may need to use filtration.
Printing B&W on B&W paper should give good blacks but some paper/developer combinations will be warm tone or strange colorations.

Please state what materials you are using so that others may further help you._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

Sorry, I am using arista vc glossy paper to enlarge b & w negatives on a color enlarger(I think. It has the three filters so I assume that means color. ) to be honest, I don't know what kind of chemicals i am using other than the brand is arista (i saw a bottle under one of the counters) because I use a community dark room. [/img]

Black and white paper can't see color, but the yellow and magenta filters in a color enlarger can effect the contrast of the Variable Contrast paper (VC) so the color enlarger can't make a brown image on B&W paper.

I can think of three things that can give brown tones to a print:

1. It's a warm tone paper, and will say so (check you specific paper at Freestylephoto.biz there are lots of Arista papers)

2. It's a paper that CAN be made to go warm with the right (or wrong) developer. Check what the darkroom is using and call or write freestyle.

3. The paper isn't getting enough development time. Ideally I like a 2 minute development time, but I also don't like to be in the darkroom for 18 hours straight, so I settle on a bare minimum of 1 minute for RC and you're better off with 1:30. This will give the paper a change to develop maximum black.

4. longshot, The paper isn't getting enough exposure. If your times are longer than 10 seconds and the aperture is around f8-f16, then you should be good.

I'm guessing it's a paper/developer combo._________________"In order to invent, you need a good imagination and a lot of junk" Thomas Edison

Are you using fresh chemicals? The filtration for VC paper only affects the contrast (ratio of difference between black, white and gray). It does nothing to change the color. If you are going to use an enlarger with a dichroic (color) head and plan to use the built in filtration, you need to find out how that filtration relates to the VC filter system. Ilford's web site should have the necessary conversion data in their technical specs. This tells you how to dial in the filter that equals a grade 1, 2, 3, etc. Where do you live in Idaho?_________________Glenn